A woman who died in the Orlando nightclub shooting shared a video on Facebook of people dancing shortly before shots rang out.

Brenda Marquez McCool, 49, was one of 49 people killed by gunman Omar Mateen on Sunday morning. Her death was confirmed by the city Monday.

She was at the club with one of her sons, 21-year-old Isaiah Henderson, NBC News reported.

The mother and son loved to go out together, NBC News reported, because Marquez McCool loved to dance.

Her daughter Khalisha Pressley told NBC News her mom had beaten cancer twice and was the "the sweetest, lovingest person in the world."

Actor Wilson Cruz, who knew Marquez McCool, paid tribute to her on Facebook by calling her a "fighter" and an advocate for the LGBT community.

"She spoke passionately about how much she loved her children," he wrote. "She was hilarious and loving and tore up the dance floor when salsa or anything was playing."

Marquez McCool's last post on Facebook, around midnight on Sunday, appears to be a video of two people dancing and enjoying the music at Pulse. Many people began to share it after the tragedy as a poignant memory of the victims.